a friend of mine gave me his macbook pro to work on after trying to get help at apple store without any luck. The problem is that i think when he was trying to upgrade os to mountain lion the process locks the disk and the i seem to remember this happened to another person i knew last year. Apple says the disk is bad but i ran the disk utility and says fine. I wish i could remember how we got the other macbook to get thru the upgrade but the disks are viewable in the disk utility after i hit the alt(option) key at startup where i then entered the recovery area. This person has time machine backups but they are from 2yrs ago and he wants to be able to keep his pictures on the existing drive. Any ideas?